Lemma 5.3 (cf. [1]})  
If \(X_0 = \operatorname{Cay}(\mathbb {Z}_n, \lbrace \pm a, \pm b\rbrace )\)  is a connected, bipartite, twin-free, non-normal, circulant graph of valency 4, then \(X_0 = \operatorname{Cay}(\mathbb {Z}_{10}, \lbrace \pm 1, \pm 3\rbrace )\) .

